Cloned games are nothing new to the games industry. You can hardly walk the isles of Gamestop or browse the listings of the iPhone App Store without coming across a clone or two [thousand]. This is especially true for many classics such as Breakout or in this case Tetris.
As a little back story for this case, Xio Interactive developed a game it called Mino which it admits was directly inspired by Tetris. When this game was discovered by The Tetris Company, it sued Xio for copyright infringement in the US District Court of New Jersey. During the course of the legal fight, Xio claimed that its use of the rules and mechanics were fair use as ideas and rules cannot be covered by copyright. Tetris argued that because almost all assets of Tetris were copied, the game infringed its copyrights. This left the Judge in the unenviable position of determining just what aspects of Tetris are not covered by copyright.
In this ruling, the Judge admitted that basic rule sets and gameplay cannot be covered by copyright. So he set about figuring out just what were the core concepts of Tetris. He ended up ruling that the basic rule set of Tetris that is not copyrightable is the idea of a game in which shapes fall from the top of the screen and must be lined up with other shapes to clear the board. As an example of a game that used this basic rule set that does not infringe the Tetris copyright, the Judge cited Dr. Mario.
The Judge then went on to rule that because Xio had copied far more than the basic rule set for Tetris, going so far as to copy the exact dimensions of the play area, the shape and color of the pieces and several other mechanics, that its use did indeed violate the Tetris copyright. The Judge also included several side by side comparisons of the two games (as seen at the top of this article) that were virtually identical. The Judge also explained that had Xio altered enough of the game, such as changing the dimensions of the play area, the shape and look of the game pieces or their behavior with each other it could have avoided the infringement claim.
So what does this ruling mean in the overall debate over game cloning? Not much really. The ruling was made in a District Court with jurisdiction only in the State of New Jersey. So it does not hold precedence outside that jurisdiction. Also, the ruling will most likely be appealed to the 3rd Circuit. Which means that it could be over ruled.
However, as an exercise, let's consider that this case has bearing across the US. Would it help those fighting against cloning of their games? Not likely. The ruling is pretty narrow in scope. While it is a win for Tetris, it is mostly a win against outright clones rather than games that have a heavy inspiration from other games. For example, it might not apply to such recent cloning examples as Tiny Tower vs Dream Heights or Radical Fishing vs Ninja Fishing. So don't start shouting in the streets that the era of game clones is dead as that is a bit premature at this stage.